(1) Field of the Invention
The present invention relates to a shooting mechanism for paint ball gun and the piston rod of the valve in the gun does not generate much vibration when shooting.
(2) Description of the Prior Art
A conventional paint ball gun includes a valve which includes a piston rod which controls the communication of the valve and the chamber in the barrel of the gun. The piston rod is hit by a strike rod so as to open the valve to introduce pressurized air into the barrel to shoot the pain ball. The piston rod is applied by the pressurized air in a direction opposite to the direction that the piston rod is hit and moved, so that the strike rod has to hit the piston rod hard enough to overcome the force applied to the piston rod and this generates a significant reaction force to the gun. How to reduce the reaction force is one of the most concerns of a satisfied pain ball gun.
US 2006003759 discloses an improved design wherein the piston rod includes an enlarged portion which defines a small chamber in the valve and the chamber is communicates with a main chamber from which the pressurized air is stored. The pressurized air in the main chamber provides limited air to the small chamber so as to assist the movement of the piston rod when the piston rod is hit by the strike rod. By this way, the strike rod does not need to apply that much of force to move the piston rod, so that the reaction force applied to the user's hand can be reduced. However, when the piston rod is hit by the strike rod, a certain part of the piston rod extends out from the valve and that part does not have any support or positioning means to hold. When the piston rod is pulled back, that part might not be able to smoothly moves back to its original position.
The present invention intends to provide a shooting mechanism for a paint ball gun wherein the valve includes a shoulder which prevents the piston rod from extending too much from the valve after being hit by the strike rod.